My feeling is that restricting bonus movement to those with Medium armor or lighter at level 7 will be sufficient to keep Bravuras* out of heavy armor.
So, yeah, they get to weary heavy armor levels 1 to 7. That's ok. It gets most powerful when they can start moving in order to take reactions. And it's the most...logical. We could get fancy and have tiers of movement with various armor levels, but I think it's sufficient to force them to choose between stacking Dex or taking a -2 AP penalty. (The abolition of the rapier...curse it's very name!...would make the choices even more interesting.)
IMO: if we could keep heavy as an option, without too much complexity it would be better.
And if you get less reactions, you get less movement. So letting heavy move during his 1 reaction seems fine.
Also, I think we could eliminate the movement counting. (Maybe)
So....
Suggestion Round up v5
Poetry in Motion.
At 3rd level, you excel at adapting opportunistically to changes in the battlefield, but it requires you to be unencumbered: If you are wearing medium armor, you can trade one attack on your next turn to take an extra reaction. If you are wearing light armor, and have multi-attack, you may trade as many reactions as you have attacks. If you use this feature to gain a reaction, you can only use your action on your next turn to take the attack action on your turn, even if you have no attacks remaining. You can only use 1 reaction per trigger.
Contingencies
At 3rd level, you can use your reaction to take the Help action. In addition, you can choose 2 reactions from the following list. You gain an additional choice at levels 7, 10, 15, and 18. Additionally, when you gain a level in this class, you can choose one of the reactions you know and replace it with another from the list.
Reaction at a Distance
At 7th level you can move as part of your reactions. When a reaction requires you to be 5’ closer than you are, you can move up to 5’ in order to be within range. This increases to 10' at level 10, and 15' at level 18.
In addition, your rapid movements make it difficult for creatures to hit you. Creatures have disavantage to hit you with oppertunity attacks.
So Crazy It Just Might Work
By 10th level your ability to improvise under pressure is unparalleled. You can spend either 1 action or 1 minute forming a plan. Choose a simple goal, and select a number of creatures (including you) up to half your Bravurae!(tm) level. They gain advantage on their next skil check to acomplish that goal. If you used an action, this bonus lasts for 1 minute. If you planned for 1 minute, it last for 10 minutes.
Overreaction
At 15th level, gain 1 additional reaction each turn.
Endgame
At 18th level, your ability to react in the face of death is nearly supernatural. When you or another creature within 30’ of you goes to zero HP or dies, you can use a reaction to force any d20 die to be either a 2 or a 19, potentially avoid death. Once you use this ability you cannot use it again until you have finished a long rest.
Contingencies
Press the Attack (Prerequisit 13 Int)
When an ally makes a weapon attack against an enemy within 5’ of you, as a reaction you can let the ally make an additional attack against the target as a bonus action. If the attack hits, it deals 1d6 extra damage.
Counter Arrow
If you are wielding a ranged or thrown weapon, and a ranged attack or damaging spell that travels within short range, your reaction to intercept the attack in mid-air. Reduce the attack's or spells damage by half your Bravurae!(tm) level . If this reduces the damage to 0, the attack misses, or spell fizzles.
Explosive Dive
When you are targeted by Area of Effect, you can use your reaction to move up to half your speed and take 1 willing creature within reach along with you, potentially escaping the zone. You are the creature prone to this movement.
First Aid: (Prerequisite 13 Wis)
When an ally takes damage, and you have a healing kit, you quickly run over and slap on a bandage before their insides become outsides. They can spend half their maximum hit dice (or any remaining if they have less than half), and immediately regain those hit points. For each die spent, they gain additional hit points equal to your proficency bonus. If the target was reduced to 0 HP, they can immidately stand up.
Timely Shove (Prerequisite 13 Str)
When a creature within 5' moves, you either give them a friendly shove to increase their movement by 10', or hamper them to reduce their movement by 10'.
Reposition
When a creature within 10’ moves, you can use your reaction to move, up to half your speed without provoking an opportunity attack.
Bait and Switch
When an enemy makes an Attack of Opportunity against you, as a reaction you may lure that enemy into overextending itself. It provokes an opportunity attack form each other creature within 5' of it except you.
Bolster Resolve (Prerequisite 13 Cha)
When an ally within 15’ makes a Wisdom or Charisma Saving Throw, you can use your reaction to give them advantage. You must be able to speak and the ally must be able to hear you.
Adjust Reaction
When a creature within 5’ is the target of a spell that requires a Dexterity Saving Throw, you may use your reaction to either grant Advantage or impose Disadvantage on the saving throw.
Skirmish
When an ally provokes an Attack of Opportunity from an enemy within 5’, use your reaction to prevent the attack.